Odd Flash

[xXTheOneRavenXx]

Good evening,

Tonight at 12:35am my wife and I were outside looking at the stars when I noticed a small flash ever so slightly southwest of Alkaid in the constellation Ursa Major. (Eastern most star in the Big Dipper) from Greenwood, Nova Scotia. The flash itself was by eye was about a magnitude or two greater then Alkaid itself. I'm not sure what it was, but it lasted only about 2-3 seconds. I guess I was looking in the right spot at the right time. I know with my job knowledge it was no plane, it had absolutely no directional movement what so ever. I just noticed it form, grow bright then fade again. Holding a pencil horizontal at arms length would have covered Alkaid and this flash, it was that close to my reference star. lol, before anyone asks, no it wasn't lightening... just a small pinpoint of light come into visibility and fade again. Could this have been a supernova of a distant star beyond Alkaid? If not, what do you think caused it?

 

[MeteorWayne]

Have you ever seen an Iridium flare? It could have been a weak one, or a flash from one of many other satellites.

Over a flare of only 2 or 3 seconds, it's very hard to detect motion for a high orbiting satellite.

About 15% of the satellites I see during my meteor sessions change brighness. Some smoothly vary, others produce short flares like you describe, and others produce very short (millisecond length) flashes.

Most flashers do repeat; the period can range from as short as a second or two, to much longer. The longest I've recorded was about 15 seconds between flashes, though I'm sure some are longer. It's just that it's hard to track flashing satellites with long periods between the flashes.

When I see such a flash, I try and watch the area around it for at least 30 seconds to see if I can capture a second flash and therefor detect the satellites motion. That makes the next flash much easier to find

Oh, and supernovas last weeks to months. Things that last seconds are either meteors or manmade

Wayne

 

[xXTheOneRavenXx]

Good afternoon Wayne,

Thank you for your response. Yes, my wife and I watched the area for about another 10 minutes to try to detect another flash. I have seen many satellites both by eye and through 10" F5, and yes your right about being able to track their path across the sky... though as the ones I viewed moved quite quickly; they were more then likely in LEO. But the flash I saw last night have no movement during the duration of the flash, and like I mentioned we could not locate a second flash even with the clear sky conditions in that area. I supposed it could have been a satellite in HEO. "If" it were a meteorite, would it actually appear as a pinpoint growing slightly in magnitude then fade quickly if it were approaching the earth in the exact direction you are looking rather then the streak of light we are all used to seeing crossing the sky? To answer your other question, no I actually haven't observed an Iridium flare.

 

[MeteorWayne]

Yeah, it doen't even have to be in HEO, just high LEO. Most people who see Iridium flares (767 km, syill considered LEO) for the first time report no movement, but when you've seen a few the motion is quite visible. It's all a matter of familiarity with the phenomenon. Of course the average Iridium flare lasts more like 10 or 15 seconds.

Over 2 or 3 seconds, motion at that rate would be very hard to notice unless it was very close to a bright star, probably closer than a pencil length.

 

[xXTheOneRavenXx]

Over 2 or 3 seconds, motion at that rate would be very hard to notice unless it was very close to a bright star, probably closer than a pencil length.

lol, nice reference I guess I learn something new everyday. I guess to catch this particular type might have been a little uncommon if it were not for that reference star. I suppose it really was right place, right time. I was just really curious to what it might have been given it's appearence/disappearence speed. I will have to keep that in mind.

 

[xXTheOneRavenXx]

Iridum 10 looks like the best candidate for what we saw as it's orbit path brings it well within our view. However the timing is off by a few hours. It's not due over Nova Scotia until about 5:24pm. Iridum 47 however has a closer time frame, but it's orbital path brings it out over the Atlantic and should be out of our view.

 

[MeteorWayne]

Well neither really seems like a good match then. A few hours later doesn't count in Iridiums, and out over the ATlantic wouldn't work from your location since it wouldn't be in the north. ANd Iridiums flare at only very specific times and locations due to their precise geometery and small reflective surface.

As I said, there are many flaring/flashing satellites and rocket bodies out there. Ones that do so intermittently or rarely would not be listed on the H-A page, since they only list sats brighter than mag +4.5 for a predictable part of their orbit (i.e intrinsic brightness, not refelctions from surfaces) and they only list Iridiums brighter than Mag 0.

There are 9 Iridiums in each plane, so ~9 minutes before and after one, there's another in the same basic orbit, offset by how much the earth has turned in that time. I will often see 3 or 4 in a row separated by 9 minutes, only one or none of which produce bright flares.

 

[xXTheOneRavenXx]

Ya, so it's highly unlikely then it was an Iridium flare. God knows what it was then.

 

[MeteorWayne]

She might now know, too busy to keep track

It was probably one of the thousands of pieces of space junk we've polluted LEO with.

If you really want to wade into it there are programs you can install on your computer and resources to access the latest TLE (Two Line Element) orbital parameters for all known satellites. (Assuming those don't get calssified )

Being a meteor guy, I just don't get into it that deep. I just document what I see and identify what I can with a modest level of time investment.

After that' it's just data in my astronomy logbook

Wayne

 

[xXTheOneRavenXx]

lol, not in too deep?? I thought your name would soon be up there with Einstein when it comes to astronomy Wayne It's okay. I just posted the question just out of curiosity. I promise not to loose any sleep over it, lol.